PHOENIX — Yet again, the NFL is changing its rules because of the Patriots.

The NFL’s 32 owners voted Wednesday to adopt a proposal that makes it illegal for an offensive player with an eligible number to declare himself ineligible and line up outside the “core” of the formation.

The rule change is a direct result of the Patriots’ ineligible/eligible tactics against the Baltimore Ravens in the AFC playoffs in January, when running back Shane Vereen declared himself ineligible but lined up as a slot receiver.

The Patriots used the tactic three times successfully to create confusion among the Ravens defenders and drive the ball down the field for a touchdown.

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The new rule states that an ineligible player must line up inside the tackle box or be flagged for a 5-yard penalty. Dean Blandino, the NFL’s head of officiating, clarified that the ineligible player couldn’t flex out more than 2 yards beyond the next interior offensive lineman.

“It’s a normal tight split,” Blandino said. “So you can basically think about the core of the formation, that’s where the player has to be.”

The new rule was proposed by the NFL’s nine-member competition committee, of which Ravens general manager Ozzie Newsome is a member. Ravens coach John Harbaugh was upset about the tactic during the playoff game — a 35-31 comeback win for the Patriots — and complained that the officials did not give his players enough time to identify the eligible and ineligible players, although referee Bill Vinovich did clearly announce over his microphone that Vereen was ineligible and should not be covered.

While the Patriots’ tactics were well within the rulebook, Rams coach Jeff Fisher, a leading member of the competition committee, said last week, “Unless we had some guidelines in place, this thing may get out of hand.”

The rule was one of eight passed this week at the owners meetings, out of 23 proposed. Four of the eight concerned player safety: extending defenseless player protection to receivers immediately after an interception; eliminating all peel-back blocks; preventing running backs from engaging in cut blocks; and not allowing a punt-block team to push their teammates into the offensive linemen.

The owners also approved: using instant replay to correct the game clock at the end of a half or overtime; carrying over a 15-yard penalty into the second half or overtime if a taunting or unsportsmanlike foul penalty is called on the final play of a half; allowing teams to open their retractable roofs at halftime if they meet several conditions; and allowing linebackers to wear numbers 40-49 as well as 50-59 and 90-99.

There were 13 rule proposals about instant replay, but only two survived: the Titans’ proposal about using replay to fix the game clock, and the Patriots’ proposal to add cameras to the goal line and sidelines, which was tabled for the NFL to research it further.

There was also a 30-40-minute discussion about the future of the extra point, and while nothing was decided, all signs point to the NFL enforcing major changes to the play, which has a 99 percent success rate over the last several years.

Competition committee chairman Rich McKay said his group will work with several head coaches over the next 30 days to devise a plan for improving the extra point, and the owners will vote on it at the next round of owners meetings in May in San Francisco.

“I think there’s a clear sentiment that there’s a movement to want change this year,” McKay said. “And the charge I think to us is to come back with a recommended proposal, do it in 30 days and give everyone a chance to vote on it.”

The discussion Wednesday included moving the line of scrimmage up to the 1½-yard line to encourage teams to go for the 2-point conversion, moving it back to the 15-yard line on kicks to make it a tougher conversion, eliminating the kick altogether and forcing teams to go for 2, and giving the defensive team 1 or 2 points if it forces a turnover and return the ball to the end zone.

“I think teams pretty much all said the same thing: It’s time to make this a football play,” McKay said. “And the way to make it a football play is No. 1, allow the defense to score.”